Major histocompatibility complex class I-related chain A (MICA) and UL16 binding protein 2 (ULBP-2) are tumor cell surface ligands that bind NK cell activating receptor NKG2D, and are prevalent in malignant brain tumors (Friese et al., 2003; Castriconi et al., 2007; Geller and Miller, 2011). The gene discussed is KLRK1; the disease is neoplasm.